The present disclosure relates to an image forming apparatus that makes a state transition between a normal state and a power saving state.
In recent years, image forming apparatuses such as copying machines and multifunction peripherals are required to have low power consumption, and therefore, in addition to the normal state under which a major job such as a printing job or the like is to be executed, is provided with a function to perform transition to the power saving state under which power consumption is made reduced. In the normal state, the image forming apparatus, when the sleep transition time has elapsed without being operated, turns off a power supply to a printing unit, a display unit, and the like, to transit to enter the power saving state.
In the power saving state, when a print job is accepted or when an operation unit is operated, the image forming apparatus turns on the power supply to the printing unit, the display unit, and the like, and performs restoration from the power saving state to the normal state. However, it is inefficient to perform restoration to the normal state frequently in a short time. Therefore, in the case of frequent restoration from the power saving state in a short time within a predetermined period, a technique has been proposed in which the sleep transition time is set to be longer after an elapse of the predetermined period.
As an index of such energy saving, the TEC value of each image forming apparatus is made public. The TEC value indicates the conceptual power consumption (kWh) for conceptual one week. The conceptually one week is made up of five business working days in which operation and sleep/off are repeated, and two business holidays in which sleep/off state remains unchanged.